Tempering-bath for steel.



JAMES CHURCHWARD, OF NEW YORK, N

TEMPERlNG-BATH FOR STEEL.

Speeifieationof Letters Patent.

Patented March 5. 1907.

Application filed September 18.1906. Serial No. 335.153.

To m' whom it 'I'H/IJ/I/ concern."

Be it known that l, J AMES (JnURcnWARn, a subject of the King of GreatBritain, residing in the borough of Manhattan, in the city, county, andState of New York, have invented certain new and useful Improvements in'lempering-Baths for Steel, of which the following is a specification.

This invention relates, as its title indicates, to baths for quenchingsteel to impart a special hardness thereto. 7

llitherto the common custom has been to heat the steel and then plungeit into Water or oil. In my United States Patent No. 832,771, of October9, 1906, I have described and claimed a quencl'iing-hath eontainingaphenol or phenol derivative mixed-With an oil or other fatty substance,and this I do not claim broadly herein; but the object of this inventionis to provide a bath containing .mercury and a fatty substance forspecial hardening, the latter being adapted for use with specialadvantages in connection with the aforesaid phenol-bath.

In carrying out the invention in an approved l'orm a suitable proportionof a phenol'such as carbolic acid (phenyl hydroxid) or creosote, (amonomethyl ph enol,) for exam plc-with some fatty substance-such asglycerin (glycerol) or linseed-oil, for exampleform the-quenching-bath.

For steel heated up to about1,400 Fahrenheit to 1,600Fahrcnheit a bathcomposed as follows, in a suitable tank or receptacle, will produce goodresults:

Carbolic acid 30% to 'Linsecdoilto 50% The bottom of said receptacle islined or covered with a layer of mercury and lard mixed together, asfollows:

Mercury 30% to 50% Lard or-fat 70% to 50% The mixture of mercury andlard or fat may cury mixture until the temperature is reduccd to about800 Fahrenheit, and then aga n plunge 1t Into the phenol-hath untilcooled; but the most simple, safest, and the most effective Way is tohave the mercury mass covered by the phenol and oil liquid, and thenwhen the heated metal comes in contact with the mercury and fat thedangerous fumes arising therefrom will be filtered by the oil and escapein a much less dan erous form, if not in an absolutely harm ess form.found in the bath of oil and phenol covering the mercury mass. Forinstance, in tempering a tool the edge or cutting part only may besubmerged in the mercury, thus giving an extremely hard edge or pointwith a toughened back, or in the case of an armor-plate an extremelyhard face Where it has rested in the mercury and a tough face where ithas not come in contact with the mercury.

The bath should be kept as cool as possible and the tool or plate shouldremain init until reduced to a temperature of 300 Fahrenheit to 500Fahrenheit. It may then be taken out and sprayed with cold Water untilabsolutely cold, when there would be no chance of semi-annealing frominternal heat.

The pro ortions of the ingredients of the quenchingath mav be variedsomewhat without departing from the spirit of the'inventioxn The wordsfatty substance or material as herein used are meant to includeglycerin, oils of all kinds, and other substances containing fattyacids.

I am aware that it has been proposed to use liquid mercury as atempering-bath aiter the steel has been rolledin horax, and t'u's I donot claim. In accordance with the present invention the mercury used ismired with some fatty substance and when used with a phenol-bath it willbe at'thebotlom with the lighter fatty substances above it.

Other great advantages are also Having thus described my invention, 1 4.A quenching-bath for steel, containing claim a phenol-bath having at itsbottom a mixture 1. A quenching-bath for steel, containing of mercurywith a fatty substance. mercury and a fatty substance. In witnesswhereof 1 have hereunto signed 5 '2. A quenching-bath for steel,containing my namejt'his 17th day of September, 1906, 15 mercury,linseed-oil, and u phenol, the merin the presence of two subscribingWitnesses.v

cury being at the bottom of the bath. JAMES ()H U ROhWAliD 3. Aquenching-bath for steel containing Witnesses: v mercury, linseed-oil,and carbolic acid, the WILLIAM J. FIRTH,

1 0 mercury being at the bottom of the bath. H. G. HOSE.

